This invention relates generally to instruments for monitoring fluid flows. More specifically the invention relates to instruments for monitoring fluid flows in conduits which may also allow an object to pass through the instrument.
In certain applications where a fluid flow rate must be determined for a flow through a conduit (or other related properties such as fluid velocity and mass flow rate), access through the bore of the conduit before, during, or after fluid flow rate determination may be desirable for additional testing and/or other operations. Flow meters known in the art often consume so much space within the bore of the conduit where the flow is to be measured, that the ability to operate other testing equipment within the bore of the conduit is heavily impaired, if not impossible. Time and other resources may be lost removing the flow meter from the bore of the conduit before other testing and/or operations may proceed.
Additionally, because flow meters known in the art consume so much space within the bore of the conduit where the flow is to be measured, these flow meters are subject to all of the consequences of such total exposure to the monitored fluid flow. For example, solid particles in the fluid flow may impair operation of such flow meters, potentially causing damage. Additionally, high flow rates may work to destroy rigid portions of the flow meter to relieve increased pressure in the fluid flow due to the presence of the flow meter.